People conveyors, as e.g. escalators and moving walkways, are usually driven by chain drives including at least one endless drive chain which extends between two turnaround portions and which is formed by a plurality of links pairwise connected by joints. Each joint is provided with a support and engagement element, typically a roller, which is configured for engagement with a corresponding turnaround element, typically a sprocket, for driving the chain. Between the turnaround portions of the chain, which are located below landing areas provided at both ends of the conveyor, the rollers are guided and supported by guide rails extending between said turnaround portions.
In order to reduce the polygonal effect, which is generated when the moving chain is deflected from a straight path of travel in the turnaround portions, and for reducing the load, which is to be carried by each roller supporting the chain on the guide rails, a large number of rollers, i.e. a large number of chain links is preferable. On the other hand, increasing the number of links may cause adverse effects, as e.g. increasing the abrasion resistance and wear of the chain, reducing the robustness of the chain and increasing the costs for production, installation and maintenance.
In consequence, it is desirable to reduce the number of chain links of the drive chain without increasing the polygonal effect and/or the load to be supported by each of the rollers.